[PATCH] prohibit slash in proc directory entry names

proc_create() needs to check that the name of an entry to be created does
not contain a '/' character.

To test, I hacked the ibmveth driver to try to call request_irq with a
bogus "foo/bar" devname.  The creation of the /proc/irq/1234/xxx entry
silently fails, as intended.  Perhaps the irq code should be made to check
for the failure.
Signed-off-by: Nathan Lynch <nathanl@austin.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/proc/generic.c

@@ -551,6 +551,11 @@ static struct proc_dir_entry *proc_create(struct proc_dir_entry **parent,
 
 	if (!(*parent) && xlate_proc_name(name, parent, &fn) != 0)
 		goto out;
+
+	/* At this point there must not be any '/' characters beyond *fn */
+	if (strchr(fn, '/'))
+		goto out;
+
 	len = strlen(fn);
 
 	ent = kmalloc(sizeof(struct proc_dir_entry) + len + 1, GFP_KERNEL);